Why a Herbarium of 7.8 Million Plants Is One of New York’s Most Valuable Resources

A plant being handsewn onto a herbarium sheet at the New York Botanical Garden (photo by Ben Hider, courtesy New York Botanical Garden)

After a corpse flower opened at the New York Botanical Garden (NYBG) last summer, drawing 30,000 visitors in the course of its brief and pungent bloom, it received the posthumous honor of becoming the three millionth specimen digitized from the Bronx institution’s herbarium. While NYBG is among New York City’s great green wonders, it’s also home to the world’s second-largest herbarium, created just after the garden was established in 1891. The William and Lynda Steere Herbarium now houses 7.8 million plant and fungal specimens, representing biodiversity from every continent. But what is a herbarium, you might ask, and why does it matter?

Amorphophallus titanum (Corpse Flower) specimen, which bloomed at the New York Botanical Garden in July 2016, the first time a corpse flower had bloomed at NYBG since 1939. The bar code at the bottom reads: 03000000, or 3 million, meaning the corpse flower is the three millionth herbarium specimen to be digitized. (courtesy New York Botanical Garden)

“Unless you work in botany, you really don’t know what a herbarium is and what this collection is, and its broad impact,” explained Dr. Matthew Pace, assistant curator to the herbarium, during a behind-the-scenes visit by Hyperallergic. Pace is a botanist studying the diversity and evolution of New World orchids. He walked me through the mounting room, digitization lab, and one of the four levels of cabinets that make up the archive of dead plants, a significant scientific resource.

Currently, NYBG is celebrating the collection inWhat in the World is a Herbarium?, installed in the Ross Gallery of its Library Building. The exhibition comes at an important moment. In a 2015 article for the journal Nature, Boer Deng reported that over “100 North American herbaria have closed since 1997, leaving just over 600 remaining,” with budget cuts and a perception of them as obsolete threatening their survival. Like the NYBG herbarium, most operate out of public view, so “it’s very challenging to make the case at these small universities that its herbarium should be kept,” Pace said. He noted that NYBG often adopts “orphan herbaria,” for instance that of the Brooklyn Botanic Garden, on loan in the Bronx while its scientific facilities are updated.

The one-room show answers the titular question — a herbarium is basically a botanical library — and includes selected specimens that represent current research, historical context, and oddities, like the corpse flower, with its voluminous purple bloom now flattened on an acid-free sheet of paper. Nearby are a swamp rose collected by NYBG scientist Daniel Atha in his documentation of natural plants in Central Park; a curare specimen from the Amazon, along with a blow dart that uses the tropical vine’s poison; and a bright flower of the purple loosestrife from Europe that’s been a highly invasive species in the United States since the 1830s. A video display features the diverse focuses of NYBG scientists, whether Jessica Allen’s investigation into how climate change is impacting lichen distribution in the Mid-Atlantic Coastal Plain or Ina Vandebroek’s connections with Caribbean immigrants in New York who have medical plant knowledge. A herbarium can offer base data for studies of climate change, invasive species, habitat loss, medicine, and conservation. Pace estimated that 20,000 hours are logged by outside visitors to the NYBG’s herbarium each year.

Installation view of What in the World is a Herbarium? at the New York Botanical Garden (photo by the author for Hyperallergic)Dr. Matthew Pace in the NYBG herbarium (photo by the author for Hyperallergic)

“We always try to tie in science to the garden displays, but this is the first time that we’ve highlighted the herbarium,” Pace said. As he described it, the technique of preserving plants has been consistent for centuries. “The actual process of making herbaria hasn’t changed since the time of Linnaeus,” he added, referencing the 18th-century Swedish botanist Carl Linnaeus, who’s recognized as the “father of taxonomy.”

Each specimen sheet, going back to the 1700s, is arranged in almost the same way, with the pressed and dried botanical, detailed notes on where and when it was found, its environment, and a description of its color before it fades. A packet is attached for seeds or broken bits, which are incredibly valuable now for noninvasive DNA testing. This rigidity of form means that it’s feasible to quickly digitize huge quantities of herbarium specimens, and NYBG has already done so for its C. V. Starr Virtual Herbarium. As they’ve taken on this monumental task, researchers have uncovered previously overlooked specimens, such as stalks of Nootka lupine collected on Roald Amundsen’s 1903–06 Northwest Passage journey.

Securing a specimen in the mounting room (photo by the author for Hyperallergic)

The mounting room is usually the first stop for specimens, where they are delicately unwrapped from newspapers printed in nearly every language. It’s encouraging to see, as a journalist in the disappearing print era, that for the botanist, newspapers remain essential. Pace noted that the material is always readily available and doesn’t damage the specimen. In turn, the papers are an unintentional representation of global culture. “You get this interesting combination of pure science and the humanities,” he said. “It’s an interesting glimpse into the world at large.” He related how a shipment of plants from a curator doing research in Tibet came wrapped in Arabic newspapers because, although they are a minority, Muslims make up a small community in the region.

A specimen being prepared in the mounting room (photo by the author for Hyperallergic)

Some specimens are complicated. Palm leaves must be spread across multiple pages, and cumbersome objects like Brazil nuts and fruit have to be lodged separately or suspended in spirits. (One of the three mounters working during my visit described a recent arrival that had nuts shaped like pangolins.) Yet it’s mostly a delicate process of placing the plant in a permanent pose that will suggest its living presence, held in place on the sheet by glue or thread. “It’s something that combines scientific knowledge and artistry,” Pace said. Duplicates are shared with other herbaria, in case of the tragic loss of an entire collection, such as when Berlin’s Botanic Garden was firebombed in 1943.

Specimens being photographed in the Digital Imaging Center (photo by the author for Hyperallergic)

A mounted specimen’s next trip is to the futuristic Digital Imaging Center, where, when I visited, four people were photographing specimens in light boxes. The resulting high-resolution images are accessible to scientists and the public through the online herbarium. “NYBG has been a leader in digitizing its plant specimens,” Pace said. “The purpose is to make our specimens as widely known as possible.” Currently, about 30,000 records are being added by staff and volunteers each month.

Following the entry into the digital archive, a specimen is placed in the climate-controlled herbarium cabinets. Even if, say, the curious shape of a spiny palm fruit doesn’t excite you, it’s incredible to be able to look at fungi collected by George Washington Carver for his research on crop diseases, moss picked on Charles Darwin’s 19th-century Beagle Voyage, and a clematis collected in 1771 on Captain James Cook’s expedition.

Moss collected on Charles Darwin’s Voyage of the Beagle (photo by the author for Hyperallergic)A specimen collected on Captain Cook’s first voyage (1768–71) (photo by the author for Hyperallergic)

It may seem obvious, but our human existence is entwined with the protection and survival of these plants. With scientific and environmental funding increasingly threatened in the United States, What in the World is a Herbarium? highlights how ecological crises and the intricacies of nature can be examined through a resource of the global present and past. One ghost of conservation on view is an 1891 chestnut tree specimen. It was collected the very year NYBG was founded, when chestnuts proliferated on the East Coast. Due to an invasive fungal disease from Asia, discovered only a few years later at the Bronx Zoo by a NYBG scientist, four billion of those chestnut trees would die over the next five decades.

“The whole purpose is to make this last forever,” Pace said of the herbarium. “There’s a connection to the people who have worked here before you and put all this care into collecting and researching these specimens. Now I’m in the same position, to be sure that scientists in the future can have that same access.”

Castanea dentata (American Chestnut) specimen, collected in the Bronx’s Van Cortlandt Park in 1891, only a few years before a NYBG scientist diagnosed chestnut blight on trees in the Bronx Zoo (courtesy New York Botanical Garden)The William and Lynda Steere Herbarium (photo by the author for Hyperallergic)An early 1900s specimen with seaweed shaped into a horse (an unusual choice for a herbarium) (photo by the author for Hyperallergic)One of the climate-controlled cabinets of the NYBG Herbarium (photo by the author for Hyperallergic)Rosa palustris (Swamp Rose) specimen collected by NYBG scientist Daniel Atha in New York City’s Central Park, where he is working to document all of the park’s naturally occurring plants (courtesy New York Botanical Garden)Specimens in the Steere Herbarium, including one of the corpse flower specimens at center (photo by the author for Hyperallergic)A specimen that has been used for molecular study (note the segment in its leaf) (photo by the author for Hyperallergic)Chondrodendron tomentosum (Curare) specimen, with a poison dart — an extract from the tropical Amazonian vine is the poison used on blow darts. (courtesy New York Botanical Garden)Specimen of Purple Loosestrife, an invasive European weed that has crowded out native American species since the 1830s, on view in What in the World is a Herbarium? (photo by the author for Hyperallergic)Congea specimen collected in Myanmar by NYBG scientist Kate Armstrong, on view in What in the World is a Herbarium? (photo by the author for Hyperallergic)Egyptian white water-lily specimen on view in What in the World is a Herbarium? (photo by the author for Hyperallergic)English oak specimen, with its acorns tied to the sheet, on view in What in the World is a Herbarium? (photo by the author for Hyperallergic)